[Selectivity tuning in multi-binary eluents for reversed-phase liquid chromatography (RPLC)]

Area of Science:

• Analytical Chemistry
• Chromatography
• Physical Chemistry

Background:

• Reversed-phase liquid chromatography (RPLC) is crucial for separating complex mixtures.
• Understanding selectivity in RPLC is key for optimizing the separation of polycyclic aromatic hydrocarbons (PAHs).
• Statistical thermodynamics provides a framework for relating molecular structure to chromatographic retention parameters.

Purpose of the Study:

• To elucidate the selectivity differences among sixteen polycyclic aromatic hydrocarbons (PAHs).
• To investigate the retention behavior of PAHs using three distinct binary solvent systems.
• To establish relationships between retention parameters and molecular structure using statistical thermodynamics in RPLC.

Main Methods:

• Utilized the retention equation and statistical thermodynamics to analyze RPLC data.
• Investigated the retention of sixteen PAHs under methanol/water, acetonitrile/water, and isopropanol/acetonitrile mobile phase conditions.
• Evaluated the unique selectivity offered by each binary solvent system for different PAH compounds.

Main Results:

• Each binary solvent system (methanol/water, acetonitrile/water, isopropanol/acetonitrile) demonstrated unique selectivity for PAHs.
• Methanol/water provided the best selectivity for acenaphthene and fluorene.
• Acetonitrile/water was optimal for fluoranthene and pyrene, while isopropanol/acetonitrile excelled for benzo[g,h,i]perylene and dibenzo[a,h]anthracene.

Conclusions:

• The study successfully explained PAH selectivity differences in RPLC based on molecular structure and retention parameters.
• A three-stepwise gradient elution using a multi-binary mobile phase is proposed for the effective separation of sixteen PAHs.
• The findings highlight the importance of solvent system selection for targeted PAH separations.